[Fulltiming]

I would look at the front height control valve and the two travel solenoids on the front six pack. If the up solenoid is not engaging, that would prevent air from going to the front air bags in travel mode while allowing air to flow to the bags in level mode. If the adjustment on the height control valve has slipped, the front would not level properly in travel mode or if the front height control valve is malfunctioning it could be exhausting air from the from air bags all the time. I had a split in the case of my height control valve that was massive resulting in replacing all my height control valves.